The desirability of harnessing and using solar energy is universally acknowledged and appreciated. There are, however, technical obstacles which have impeded our progress in tapping the sun's energy.
One serious impediment has been the cost of purifying silicon, the key ingredient in solar cells which convert solar radiation to electrical energy. The silicon purification techniques heretofore suggested and/or used have not proved to be sufficiently economical and effective to justify widespread commercial adoption and use. Some of the prior art techniques and their deficiencies are mentioned in the first column of U.S. Pat. No. 3,148,131 issued Sept. 8, 1964.
There is also a need for more efficient and effective techniques for purifying materials other than silicon, including metals and other semiconductors.